using System;
using System.Globalization;
using System.Windows.Data;

namespace Orm.Toolkit.Telerik.Windows.Controls
{
    /// <summary>
    /// Convert <see cref="DateTime"/> object to <see cref="TimeSpan"/>.
    /// </summary>
    [ValueConversion(typeof(DateTime), typeof(TimeSpan))]
    public class DateTimeToTimeSpanConverter : IValueConverter
    {
        /// <summary>
        /// Static instance.
        /// </summary>
        public static readonly DateTimeToTimeSpanConverter Instance = new DateTimeToTimeSpanConverter();

        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <param name="value">The value produced by the binding source.</param>
        /// <param name="targetType">The type of the binding target property.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value != null)
            {
                return ((DateTime)value).TimeOfDay;
            }

            return TimeSpan.Zero;
        }

        /// <summary>
        /// Do nothing when try to convert value back.
        /// </summary>
        /// <param name="value">The value that is produced by the binding target.</param>
        /// <param name="targetType">The type to convert to.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {

            return Binding.DoNothing;

        }
    }
}